No group immediately claimed responsibility for the bombings. But
Sunni Islamist militants have been regaining ground in Iraq,
particularly in the western province of Anbar where they overran two
cities on January 1.

Since then, more than 1,000 people have been killed across the
country, building on a trend of intensifying violence that made last
year Iraq's bloodiest since 2008, when sectarian warfare began to
abate from its height.

On Thursday, bombs were detonated in the predominantly Shi'ite
neighborhoods of Sadr City, Karrada, Hurriya, Ubaidi and Shaab.
Civilians from Iraq's Shi'ite majority are often targeted by Sunni
insurgents.

Another explosion killed three people in the commercial Bab
al-Sharqie district, near a bridge across the river Tigris leading
to the heavily-fortified "Green Zone", home to the prime minister's
office and several Western embassies.

In recent days, militants have staged a series of attacks near the
Green Zone and outside the Ministry of Foreign Affairs, heightening
concerns about Iraq's ability to protect strategic sites as security
deteriorates.

The city of Falluja is currently surrounded and under shelling from
the Iraqi army in preparation for a possible ground assault to end a
month-long standoff with Sunni anti-government fighters inside the
Anbar city.

"MANY CASUALTIES" LIKELY

The militants include members of the Islamic State in Iraq and the
Levant (ISIL) — a Sunni group also active in neighboring Syria's
civil war.

"We believe that storming Falluja as soon as possible is much better
than the current situation," a senior security official told Reuters
on condition of anonymity. "Yes, there will be many casualties, but
it's better than this strain on army resources."

The official said a ground assault would not be launched until
security forces finished battling militants in two small towns that
are important entry points to Falluja. Communications have also been
cut.

"The militants have booby-trapped roads, homes, animals and even
dead bodies inside Falluja, so we have to keep the communications
down as they use mobile signal to blow up these traps," the official
said.

Maliki has appealed for international support and weapons to fight
al Qaeda. But critics say his own policies towards Iraq's
once-dominant Sunni community are at least partly to blame for
reviving an insurgency that had peaked in 2006-07.

Some tribes in Sunni-dominated Anbar support or have aligned
themselves with ISIL against Maliki's Shi'ite-led government, which
they accuse of abuses against their sect.

Others deplore ISIL's violent tactics and have joined forces with
the army to fight the group and its allies in and around Anbar's
city of Ramadi, also overrun by militants last month but now largely
back under government control.

The United Nations said it had delivered aid including tents,
medicine, water and food parcels to some of the 45,000 families that
have been displaced by the conflict in Anbar.

"The U.N. continues to hold discussions with senior political
figures in an attempt to assist in paving the ground for a political
solution to the crisis, calling on all to show national unity and
address the root causes of violence in Iraq," U.N. envoy Nikolay
Mladenov said in a statement.